/* ---------------------------------------------------------------------------
* Truevision Targa Reader/Writer
* $Id: targa.h,v 1.7 2003/06/21 09:30:53 emikulic Exp $
*
* Copyright (C) 2001-2003, Emil Mikulic.
*
* Source and binary redistribution of this code, with or without
* changes, for free or for profit, is allowed as long as this copyright
* notice is kept intact.  Modified versions have to be clearly marked
* as modified.
*
* This code is provided without any warranty.  The copyright holder is
* not liable for anything bad that might happen as a result of the
* code.
* -------------------------------------------------------------------------*/

#ifndef TGAPARSER_H
#define TGAPARSER_H

#include <stdio.h>
#ifndef _MSC_VER
# include <inttypes.h>
#else /* MSVC */
typedef unsigned __int8  uint8_t;
typedef unsigned __int16 uint16_t;
typedef unsigned __int32 uint32_t;
#endif

#define BIT(index) (1 << (index))

#ifdef _BIG_ENDIAN
# define htole16(x) ( (((x) & 0x00FF) << 8) | (((x) & 0xFF00) >> 8) )
# define letoh16(x) htole16(x)
#else /* little endian */
# define htole16(x) (x)
# define letoh16(x) (x)
#endif /* endianness */

#ifdef __cplusplus 
extern "C" {
#endif

	/* Targa image and header fields -------------------------------------------*/
	typedef struct
	{
		/* Note that Targa is stored in little-endian order */
		uint8_t     image_id_length;

		uint8_t     color_map_type;
		/* color map = palette */
#define TGA_COLOR_MAP_ABSENT    0
#define TGA_COLOR_MAP_PRESENT   1

		uint8_t     image_type;
#define TGA_IMAGE_TYPE_NONE          0 /* no image data */
#define TGA_IMAGE_TYPE_COLORMAP      1 /* uncompressed, color-mapped */
#define TGA_IMAGE_TYPE_BGR           2 /* uncompressed, true-color */
#define TGA_IMAGE_TYPE_MONO          3 /* uncompressed, black and white */
#define TGA_IMAGE_TYPE_COLORMAP_RLE  9 /* run-length, color-mapped */
#define TGA_IMAGE_TYPE_BGR_RLE      10 /* run-length, true-color */
#define TGA_IMAGE_TYPE_MONO_RLE     11 /* run-length, black and white */

		/* color map specification */
		uint16_t    color_map_origin;   /* index of first entry */
		uint16_t    color_map_length;   /* number of entries included */
		uint8_t     color_map_depth;    /* number of bits per entry */

		/* image specification */
		uint16_t    origin_x;
		uint16_t    origin_y;
		uint16_t    width;
		uint16_t    height;
		uint8_t     pixel_depth;

		uint8_t     image_descriptor;
		/* bits 0,1,2,3 - attribute bits per pixel
		* bit  4       - set if image is stored right-to-left
		* bit  5       - set if image is stored top-to-bottom
		* bits 6,7     - unused (must be set to zero)
		*/
#define TGA_ATTRIB_BITS (uint8_t)(BIT(0)|BIT(1)|BIT(2)|BIT(3))
#define TGA_R_TO_L_BIT  (uint8_t)BIT(4)
#define TGA_T_TO_B_BIT  (uint8_t)BIT(5)
#define TGA_UNUSED_BITS (uint8_t)(BIT(6)|BIT(7))
		/* Note: right-to-left order is not honored by some Targa readers */

		uint8_t *image_id;
		/* The length of this field is given in image_id_length, it's read raw
		* from the file so it's not not guaranteed to be zero-terminated.  If
		* it's not NULL, it needs to be deallocated.  see: tga_free_buffers()
		*/

		uint8_t *color_map_data;
		/* See the "color map specification" fields above.  If not NULL, this
		* field needs to be deallocated.  see: tga_free_buffers()
		*/

		uint8_t *image_data;
		/* Follows image specification fields (see above) */

		/* Extension area and developer area are silently ignored.  The Targa 2.0
		* spec says we're not required to read or write them.
		*/

	} tga_image;



	/* For decoding header bits ------------------------------------------------*/
	uint8_t tga_get_attribute_bits(const tga_image *tga);
	int tga_is_right_to_left(const tga_image *tga);
	int tga_is_top_to_bottom(const tga_image *tga);
	int tga_is_colormapped(const tga_image *tga);
	int tga_is_rle(const tga_image *tga);
	int tga_is_mono(const tga_image *tga);



	/* Error handling ----------------------------------------------------------*/
	typedef enum {
		TGA_NOERR,
		TGAERR_FOPEN,
		TGAERR_EOF,
		TGAERR_WRITE,
		TGAERR_CMAP_TYPE,
		TGAERR_IMG_TYPE,
		TGAERR_NO_IMG,
		TGAERR_CMAP_MISSING,
		TGAERR_CMAP_PRESENT,
		TGAERR_CMAP_LENGTH,
		TGAERR_CMAP_DEPTH,
		TGAERR_ZERO_SIZE,
		TGAERR_PIXEL_DEPTH,
		TGAERR_NO_MEM,
		TGAERR_NOT_CMAP,
		TGAERR_RLE,
		TGAERR_INDEX_RANGE,
		TGAERR_MONO
	} tga_result;

	const char *tga_error(const tga_result errcode);



	/* Load/save ---------------------------------------------------------------*/
	tga_result tga_read(tga_image *dest, const char *filename);
	tga_result tga_read_from_FILE(tga_image *dest, FILE *fp);
	tga_result tga_write(const char *filename, const tga_image *src);
	tga_result tga_write_to_FILE(FILE *fp, const tga_image *src);



	/* Convenient writing functions --------------------------------------------*/
	tga_result tga_write_mono(const char *filename, uint8_t *image,
		const uint16_t width, const uint16_t height);

	tga_result tga_write_mono_rle(const char *filename, uint8_t *image,
		const uint16_t width, const uint16_t height);

	tga_result tga_write_bgr(const char *filename, uint8_t *image,
		const uint16_t width, const uint16_t height, const uint8_t depth);

	tga_result tga_write_bgr_rle(const char *filename, uint8_t *image,
		const uint16_t width, const uint16_t height, const uint8_t depth);

	/* These functions will use tga_swap_red_blue to MODIFY your image data */
	tga_result tga_write_rgb(const char *filename, uint8_t *image,
		const uint16_t width, const uint16_t height, const uint8_t depth);

	tga_result tga_write_rgb_rle(const char *filename, uint8_t *image,
		const uint16_t width, const uint16_t height, const uint8_t depth);



	/* Manipulation ------------------------------------------------------------*/
	tga_result tga_flip_horiz(tga_image *img);
	tga_result tga_flip_vert(tga_image *img);
	tga_result tga_color_unmap(tga_image *img);

	uint8_t *tga_find_pixel(const tga_image *img, uint16_t x, uint16_t y);
	tga_result tga_unpack_pixel(const uint8_t *src, const uint8_t bits,
		uint8_t *b, uint8_t *g, uint8_t *r, uint8_t *a);
	tga_result tga_pack_pixel(uint8_t *dest, const uint8_t bits,
		const uint8_t b, const uint8_t g, const uint8_t r, const uint8_t a);

	tga_result tga_desaturate(tga_image *img,
		const int cr, const int cg, const int cb, const int dv);
	tga_result tga_desaturate_rec_601_1(tga_image *img);
	tga_result tga_desaturate_rec_709(tga_image *img);
	tga_result tga_desaturate_itu(tga_image *img);
	tga_result tga_desaturate_avg(tga_image *img);
	tga_result tga_convert_depth(tga_image *img, const uint8_t bits);
	tga_result tga_swap_red_blue(tga_image *img);

	void tga_free_buffers(tga_image *img);



#ifndef TGA_KEEP_MACROS /* useful for targa.c */
# undef htole16
# undef letoh16
#endif

#ifdef __cplusplus
} // extern C
#endif

#endif /* !TGAPARSER_H */
/* vim:set tabstop=4 shiftwidth=4 textwidth=78 expandtab: */